code: def cov(
      x1: None,
      x2: None = None,
      /,
      *,
      rowVar: bool = True,
      bias: bool = False,
      ddof: Optional[int] = None,
      fweights: Optional[None] = None,
      aweights: Optional[None] = None,
      dtype: Optional[type] = None,
  ) -> None:
      raise IvyNotImplementedException()
  
file_path: ivy/ivy/functional/backends/mxnet/experimental/statistical.py
imports: from typing import Union, Optional, Tuple, Sequence
  import mxnet
  from ivy.utils.exceptions import IvyNotImplementedException
label_desc: Use image node_id 8 for calling a global function with example usage: cov() without return types